Is my propeller sized correctly?

[ForeverDes]

Howdy all.
I've been wondering if my propeller is sized and pitched well for my New Horizons 26. I have a Atomic Four, 30 hp gas engine, 1:1 direct drive shaft, and a 13:8 2 blade propeller. My hull speed is about 6.2 knots. At idle speed I move about 4 knots @ 900 rpm, but almost any increase in the throttle and the engine revs to just over 2k rpm and I move at 4.8 knots, give or take. It seems to me a deeper pitched propeller would help increase thrust while keeping the rpm's lower (I'd like to reach hull speed in flat water at around 1800 rpms), but from a few online propeller size calculators, I'm being recommended around a 12x6.4 in 2 or 3 blade, or an 11x6.2 in 4 blade props. Since this runs counter to my intuition on what's needed, I'd love to hear what more experienced cruisers think.